Diffusion-weighted MR and apparent diffusion coefficient in the evaluation of severe brain injury

Purpose: To study apparent diffusion coefficient (ADC) maps in severely brain-injured patients.

Material and Methods: Four deeply comatose patients with severe brain injury were investigated with single-shot, diffusion-weighted, spin-echo echoplanar imaging. The tetrahedral diffusion gradient configuration and four iterations of a set of b-values (one time of 0 mm2/s, and four times of 1000 mm2/s) were used to create isotropic ADC maps with high signal-to-noise ratio. ADC values of gray and white matter were compared among patients and 4 reference subjects.

Results: One patient was diagnosed as clinically brain dead after the MR examination. The patient's ADC values of gray and white matter were significantly lower than those of 3 other brain-injured patients. In addition the ADC value of white matter was significantly lower than that of gray matter.

Conclusion: The patient with fatal outcome shortly after MR examination differed significantly from other patients with severe brain injury but non-fatal outcome, with regard to ADC values in gray and white matter. This might indicate a prognostic value of ADC maps in the evaluation of traumatic brain injury.

Long-lasting coma

In this report, we describe the case of a patient who has remained in a comatose state for more than one year after a traumatic and hypoxic brain injury. This state, which we refer to as long-lasting coma (LLC), may be a disorder of consciousness with significantly different features from those of conventional coma, the vegetative state, or brain death. On the basis of clinical, neurophysiological and neuroimaging data, we hypothesize that a multilevel involvement of the ascending reticular activating system is required in LLC. This description may be useful for the identification of other patients suffering from this severe disorder of consciousness, which raises important ethical issues.

Neuroanatomical basis for traumatic coma: clinical and magnetic resonance correlates

In this paper, the relationship between brain lesion localization (verified by magnetic resonance imaging (MRI)) and the severity of traumatic brain injury (TBI) and its outcomes is presented. Magnetic resonance studies in different modes (T1, T2, FLAIR, DWI, DTI, T2 * GRE, SWAN) were performed in 162 patients with acute TBI. Statistical analysis was done using Statistica 6, 8 software and R programming language. A new advanced MRI-based classification of TBI was introduced implying the assessment of hemispheric and brainstem traumatic lesions level and localization. Statistically significant correlations were found between the Glasgow coma and outcome scales scores (p < 0.001), and the proposed MRI grading scale scores, which means a high prognostic value of the new classification. The knowledge of injured brain microanatomy coming from sensitive neuroimaging, in conjunction with the assessment of mechanisms, aggravating factors and clinical manifestation of brain trauma is the basis for the actual predictive model of TBI. The proposed advanced MRI classification contributes to this concept development.

[Coma after lucid interval--severe secondary alteration of consciousness following multiple trauma]

A 71-year-old man sustains multiple fractures in an accident; after a lucid interval he deteriorates neurologically and becomes comatose. Intracranial hemorrhage, status epilepticus, adverse drug reactions, toxic-metabolic, ischemic or infectious causes are subsequently ruled out. Development of petechiae and thrombopenia raises the possibility of fat embolism syndrome, which is confirmed in a MRI of the head 72 hours after the accident. We discuss current aetiologic concepts as well as diagnosis and clinical course of the cerebral fat embolism syndrome.

Establishing a prognosis for functional outcome during coma recovery

PRIMARY OBJECTIVE

One of the most challenging tasks for clinicians caring for survivors of severe brain injury (BI) is establishing a prognosis, for long-term functional outcome, while the patient is unconscious. The objective of this article is to report findings regarding the prediction of functional outcomes 1-year after severe BI using data available when the patient is unconscious.

RESEARCH DESIGN

Longitudinal prognostication study.

METHODS AND PROCEDURES

Persons unconscious after severe BI who present to inpatient (IP) rehabilitation hospitals in the Midwestern US are enrolled in an ongoing study. Each subject is followed for 1-year and the final outcome interview includes approximately 70 questions; 32 of these questions are from the Craig Handicap Assessment and Reporting Technique (CHART). A sample of 63 persons was abstracted from the study database to examine the predictability of 42 independent variables and 16 dichotomous outcomes.

MAIN OUTCOMES AND RESULTS

Twelve of the 16 dichotomous outcomes were found to be significantly predictable (p < 0.05). These involve activity, participation, environment and quality of life outcomes. Ten predictors were found to be significant (p < 0.05): aetiology (Closed Head Injury vs. Other BI), presence of urinary tract infection (UTI), seizure, hypertension during IP rehabilitation, veteran benefit eligibility, health insurance, marital status at injury, whether or not recovery of consciousness occurred within 1 year, the number of days between injury and admission to acute rehabilitation and the average length of IP rehabilitation stay. Eight of the 10 variables are available early after injury or when the patient is unconscious.

Search for clinical and neurophysiological prognostic patterns of brain coma outcomes in children

OBJECTIVE

The aim of the study was to evaluate the possible predictive values of clinical examinations combined with the recordings of electroencephalography and brainstem auditory-evoked potentials in traumatic coma of pediatric patients.

MATERIAL AND METHODS

A total of 43 children in coma with severe acute head trauma were included in the study. They were investigated and treated in pediatric intensive care unit using standard evaluation and treatment protocol. Evaluation of coma was performed using Glasgow Coma Scale. Electroencephalography for 35 patients and brainstem auditory-evoked potentials for 24 patients were recorded.

RESULTS

Glasgow coma scale statistic pool median was equal to 4 points as measured in presence of brain edema, meanwhile it was 6 as measured in absence of edema. In case of supratentorial damage, median duration of consciousness recovery was 10 days. In absence of above-mentioned supratentorial damage, recovery of the consciousness was earlier - median was 5 days. Determined duration of artificial lung ventilation was statistically significantly shorter for those who had edema (P=0.048). In 20 patients (57% of all cases), constant or alternating slow wave activity was observed during the first electroencephalographic recording. In other cases, "alpha coma" or low amplitude of arrhythmic activity and local slowing activity corresponding to brain damage seen on computerized tomography were recorded. For 24 patients, brainstem auditory-evoked potentials were recorded. In 9 cases, they were abnormal; in these cases, the consciousness of the patients recovered after 44 days or did not recover.

CONCLUSIONS

Glasgow coma scale results alone may have limited prognostic value in absence of other objective neurophysiologic investigation data concerning the coma outcome in children. Prognosis may be worse if pathological brainstem auditory-evoked potentials correlate with pathological dynamic changes in electroencephalography and brain lesions, diagnosed during computerized tomography scan.

Prognosis Following Severe Head Injury: Development and Validation of a Model for Prediction of Death, Disability, and Functional Recovery

BACKGROUND

A prognostic model for head trauma patients is useful only if it predicts clinically relevant outcomes accurately on new subjects in various settings. Most existing models consider only dichotomous outcome and have not been tested externally. We developed and validated a rule for prediction of three functional outcome states after severe head injury, using information from day 1.

METHODS

The model was developed in a cohort of 304 adults who were admitted to a Dutch trauma center and had survived and remained comatose for >24 hours following severe head injury. We used ordinal logistic regression analysis to predict the extended Glasgow Outcome Scale after > or =12 months, merged into three categories. We preselected five known predictors of outcome and used bootstrapping techniques to avoid statistical overfitting. The performance of the model was subsequently tested in a cohort of 122 patients from an unrelated hospital.

RESULTS

The model contained age (p < 0.0001), best motor response on day 1 (p = 0.002), pupil response after resuscitation (p = 0.005), computed tomography findings (p = 0.004), and presence of arterial hypotension (p = 0.37) as predictor variables. In the external validation cohort, the model showed adequate agreement between observed and predicted outcome probabilities (calibration). The model had a good ability to discriminate patients with different outcomes (c-statistic 0.808). The predictive accuracy was 66% when the model was used to classify patients across the three outcome categories.

CONCLUSIONS

We have developed a practical model for predicting the probability of death, survival with major disability, and functional recovery in patients who are comatose 24 hours after severe head injury. The model performed well in an external setting, indicating that measures to avoid statistical overfitting were successful.

Early clinical predictive factors during coma recovery

In severe brain injury patients few studies have examined the role of early clinical factors emerging before recovery of consciousness. Patients suffering from vegetative state and minimally conscious state in fact may need variable periods of time for recovery of the ability to follow commands. In a previous study we retrospectively examined a population of very severe traumatic brain injury patients with coma duration of at least 15 days (prolonged coma), and we found, as significant predictive factors for the final outcome, the time interval from brain injury to the recovery of the following clinical variables: optical fixation, spontaneous motor activity and first safe oral feeding. Psychomotor agitation and bulimia during coma recovery were also favourable prognostic factors for the final outcome. In a further study, also as for the neuropsychological recovery, the clinical variable with the best significant predictive value was the interval from head trauma to the recovery of safe oral feeding. In the present study the presence of psychomotor agitation diagnosed by means of LCF (score 4 = confused-agitated) at the admission time in rehabilitation predicted a statistically significant better outcome at the discharge time in comparison with patients without agitation.

[Cerebral circulatory autoregulation as a guide for controlling the parameters of assisted ventilation in acute severe brain injury]

The paper presents the results of cerebral circulation (CC) in 17 ventilated patients with severe brain injury in its acute phase. All the patients developed traumatic subarachnoidal hemorrhage, which was accompanied with angiospasm in the majority of cases. Doppler transcranial study (DTCS) was performed, by using the carotid compression test; the findings correlated with paCO2 and CV parameters. A dynamic study was performed every two days starting from their admission to an intensive care unit to the recovery from coma or normalization of CC parameters. The dilation and constriction components of the CC reserve were assessed from the results of this test and continued to be controlled during therapy. Thus, this paper shows the possibility of goal-oriented correction of CC autoregulation and optimization by selecting the parameters of assisted ventilation and by changing paCO2 under the guidance of Doppler transcranial study.

Predicting one year clinical outcome in traumatic brain injury (TBI) at the beginning of rehabilitation

Predicting long-term clinical outcome for patients with traumatic brain injury (TBI) at the beginning of rehabilitation provides essential information for counseling of the family and priority-setting for the limited resources in intensive rehabilitation. The objective of this study is to work out the probability of the one-year outcome at the beginning of rehabilitation. Sixty-eight patients with moderate-to-severe TBI and known one-year outcome were employed for outcome prediction using the logistic regression model. A large number of prospectively collected data at admission (age, Glasgow Coma Scale [GCS] Score, papillary response), during intensive care unit (ICU) management (duration of coma, intracranial pressure [ICP] and its progress) and at the beginning of rehabilitation (baseline Functional Independence Measure [FIM], Neuro-behavioral Cognitive Status Examination [NCSE] and Functional Movement Assessment [FMA]) were available for preliminary screening by univariate analysis. Six prognostic factors (age, GCS, duration of coma, baseline FIM, NCSC and FMA) were utilized for the final logistic regression model. Age, GCS and baseline FIM at the beginning of rehabilitation have been found to be independent predictors for one-year outcome. The accuracy of prediction for a good Glasgow Outcome Score is 68% and an outcome for disability (either moderate or severe) is 83%. Validation of this model using a new set of data is required.

Rehabilitative management of patients with disorders of consciousness: grand rounds

BACKGROUND

There are no standards of care to guide the selection of rehabilitation assessment and treatment procedures for patients with disorders of consciousness. Recently, consensus-based recommendations for management of patients in the vegetative and minimally conscious states have been developed and disseminated in neurology and neurorehabilitation. This is an important first step toward achieving evidence-based guidelines of care.

OBJECTIVE

Using a "Grand Rounds" format, we illustrate the application of consensus-based diagnostic, prognostic, and treatment recommendations in a patient who sustained severe traumatic brain injury with prolonged alteration in consciousness. After discussing the salient features of the case, we summarize the basic tenets of clinical care for this population.

Patients who talk and deteriorate: a new look at an old problem

BACKGROUND AND METHODS

We sought to review established prognostic indicators applied to Asian population, and to identify new risk factors for deterioration in patients who talked and deteriorated after traumatic brain injury (TBI). This retrospective study used our prospectively maintained TBI database. From August 1999 to July 2001, 324 patients were admitted to the neurosurgical intensive care unit (ICU). Thirty-eight patients (11.8%) talked between injury and subsequent deterioration into coma. Independent outcome predictors were studied.

RESULTS AND CONCLUSION

Fourteen patients had subdural haematomas, 9 extradural haematomas, 19 contusions/haematomas and 3 subarachnoid haemorrhages. 81.5% of the patients had mass lesions potentially requiring surgery. Twenty patients had good functional recovery at 6 months (Glasgow Outcome Score 4 and 5); 18 were dead or vegetative. Age, gender, type of intracranial lesion and presence of coagulopathy were significantly correlated with outcome. Intracranial haematomas continue to be most significant in patients who talk and deteriorate. Coagulopathy was the strongest prognostic predictor of poor outcome with fibrinolytic parameters being reliable prognostic markers of head injury. Early identification, continued monitoring and treatment of coagulopathy should be our new look at improving outcome of these patients.

Battlefield advanced trauma life support

Prevent secondary injury by: Preventing hypoxia, hypercarbia and hypovolaemia. Giving oxygen if available and ensure a clear airway at all times. Treating fits with diazepam in appropriate doses. Establishing a working diagnosis. Searching for associated injuries. Constantly repeating the mini-neurological examination. Identifying and evacuating appropriate casualties to a neurosurgical unit.

Functional MR imaging assessment of a non-responsive brain injured patient

Functional magnetic resonance imaging (fMRI) was requested to assist in the evaluation of a comatose 38-year-old woman who had sustained multiple cerebral contusions from a motor vehicle accident. Previous electrophysiologic studies suggested absence of thalamocortical processing in response to median nerve stimulation. Whole-brain fMRI was performed utilizing visual, somatosensory, and auditory stimulation paradigms. Results demonstrated intact task-correlated sensory and cognitive blood oxygen level dependent (BOLD) hemodynamic response to stimuli. Electrodiagnostic studies were repeated and evoked potentials indicated supratentorial recovery in the cerebrum. At 3-months post trauma the patient had recovered many cognitive & sensorimotor functions, accurately reflecting the prognostic fMRI evaluation. These results indicate that fMRI examinations may provide a useful evaluation for brain function in non-responsive brain trauma patients.